<template>
    MyLeft组件
    <div>
        count: {{ count }}
        <button @click="count++">+1</button>
    </div>
</template>
<script setup>
import { ref,onMounted,onUnmounted,onActivated,onDeactivated } from 'vue';
const count = ref(0);
onMounted(() => {
    console.log('MyLeft组件被挂载');
});
onUnmounted(() => {
    console.log('MyLeft组件被卸载');
});
onActivated(() => {
    console.log('MyLeft组件被激活');
});
onDeactivated(() => {
    console.log('MyLeft组件被缓存了');
});
</script>